net/sunrpc/auth_gss/auth_gss.c

   1 /*
   2  * linux/net/sunrpc/auth_gss/auth_gss.c
   3  *
   4  * RPCSEC_GSS client authentication.
   5  *
   6  *  Copyright (c) 2000 The Regents of the University of Michigan.
   7  *  All rights reserved.
   8  *
   9  *  Dug Song       <dugsong@monkey.org>
  10  *  Andy Adamson   <andros@umich.edu>
  11  *
  12  *  Redistribution and use in source and binary forms, with or without
  13  *  modification, are permitted provided that the following conditions
  14  *  are met:
  15  *
  16  *  1. Redistributions of source code must retain the above copyright
  17  *     notice, this list of conditions and the following disclaimer.
  18  *  2. Redistributions in binary form must reproduce the above copyright
  19  *     notice, this list of conditions and the following disclaimer in the
  20  *     documentation and/or other materials provided with the distribution.
  21  *  3. Neither the name of the University nor the names of its
  22  *     contributors may be used to endorse or promote products derived
  23  *     from this software without specific prior written permission.
  24  *
  25  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  26  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  27  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  28  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  29  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  30  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  31  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  32  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  33  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  34  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  35  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38
  39 #include <linux/module.h>
  40 #include <linux/init.h>
  41 #include <linux/types.h>
  42 #include <linux/slab.h>
  43 #include <linux/sched.h>
  44 #include <linux/pagemap.h>
  45 #include <linux/sunrpc/clnt.h>
  46 #include <linux/sunrpc/auth.h>
  47 #include <linux/sunrpc/auth_gss.h>
  48 #include <linux/sunrpc/svcauth_gss.h>
  49 #include <linux/sunrpc/gss_err.h>
  50 #include <linux/workqueue.h>
  51 #include <linux/sunrpc/rpc_pipe_fs.h>
  52 #include <linux/sunrpc/gss_api.h>
  53 #include <asm/uaccess.h>
  54
  55 static const struct rpc_authops authgss_ops;
  56
  57 static const struct rpc_credops gss_credops;
  58 static const struct rpc_credops gss_nullops;
  59
  60 #define GSS_RETRY_EXPIRED 5
  61 static unsigned int gss_expired_cred_retry_delay = GSS_RETRY_EXPIRED;
  62
  63 #ifdef RPC_DEBUG
  64 # define RPCDBG_FACILITY        RPCDBG_AUTH
  65 #endif
  66
  67 #define GSS_CRED_SLACK          (RPC_MAX_AUTH_SIZE * 2)
  68 /* length of a krb5 verifier (48), plus data added before arguments when
  69  * using integrity (two 4-byte integers): */
  70 #define GSS_VERF_SLACK          100
  71
  72 struct gss_auth {
  73         struct kref kref;
  74         struct rpc_auth rpc_auth;
  75         struct gss_api_mech *mech;
  76         enum rpc_gss_svc service;
  77         struct rpc_clnt *client;
  78         /*
  79          * There are two upcall pipes; dentry[1], named "gssd", is used
  80          * for the new text-based upcall; dentry[0] is named after the
  81          * mechanism (for example, "krb5") and exists for
  82          * backwards-compatibility with older gssd's.
  83          */
  84         struct dentry *dentry[2];
  85 };
  86
  87 /* pipe_version >= 0 if and only if someone has a pipe open. */
  88 static int pipe_version = -1;
  89 static atomic_t pipe_users = ATOMIC_INIT(0);
  90 static DEFINE_SPINLOCK(pipe_version_lock);
  91 static struct rpc_wait_queue pipe_version_rpc_waitqueue;
  92 static DECLARE_WAIT_QUEUE_HEAD(pipe_version_waitqueue);
  93
  94 static void gss_free_ctx(struct gss_cl_ctx *);
  95 static const struct rpc_pipe_ops gss_upcall_ops_v0;
  96 static const struct rpc_pipe_ops gss_upcall_ops_v1;
  97
  98 static inline struct gss_cl_ctx *
  99 gss_get_ctx(struct gss_cl_ctx *ctx)
 100 {
 101         atomic_inc(&ctx->count);
 102         return ctx;
 103 }
 104
 105 static inline void
 106 gss_put_ctx(struct gss_cl_ctx *ctx)
 107 {
 108         if (atomic_dec_and_test(&ctx->count))
 109                 gss_free_ctx(ctx);
 110 }
 111
 112 /* gss_cred_set_ctx:
 113  * called by gss_upcall_callback and gss_create_upcall in order
 114  * to set the gss context. The actual exchange of an old context
 115  * and a new one is protected by the inode->i_lock.
 116  */
 117 static void
 118 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
 119 {
 120         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 121
 122         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
 123                 return;
 124         gss_get_ctx(ctx);
 125         rcu_assign_pointer(gss_cred->gc_ctx, ctx);
 126         set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 127         smp_mb__before_clear_bit();
 128         clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
 129 }
 130
 131 static const void *
 132 simple_get_bytes(const void *p, const void *end, void *res, size_t len)
 133 {
 134         const void *q = (const void *)((const char *)p + len);
 135         if (unlikely(q > end || q < p))
 136                 return ERR_PTR(-EFAULT);
 137         memcpy(res, p, len);
 138         return q;
 139 }
 140
 141 static inline const void *
 142 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
 143 {
 144         const void *q;
 145         unsigned int len;
 146
 147         p = simple_get_bytes(p, end, &len, sizeof(len));
 148         if (IS_ERR(p))
 149                 return p;
 150         q = (const void *)((const char *)p + len);
 151         if (unlikely(q > end || q < p))
 152                 return ERR_PTR(-EFAULT);
 153         dest->data = kmemdup(p, len, GFP_NOFS);
 154         if (unlikely(dest->data == NULL))
 155                 return ERR_PTR(-ENOMEM);
 156         dest->len = len;
 157         return q;
 158 }
 159
 160 static struct gss_cl_ctx *
 161 gss_cred_get_ctx(struct rpc_cred *cred)
 162 {
 163         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 164         struct gss_cl_ctx *ctx = NULL;
 165
 166         rcu_read_lock();
 167         if (gss_cred->gc_ctx)
 168                 ctx = gss_get_ctx(gss_cred->gc_ctx);
 169         rcu_read_unlock();
 170         return ctx;
 171 }
 172
 173 static struct gss_cl_ctx *
 174 gss_alloc_context(void)
 175 {
 176         struct gss_cl_ctx *ctx;
 177
 178         ctx = kzalloc(sizeof(*ctx), GFP_NOFS);
 179         if (ctx != NULL) {
 180                 ctx->gc_proc = RPC_GSS_PROC_DATA;
 181                 ctx->gc_seq = 1;        /* NetApp 6.4R1 doesn't accept seq. no. 0 */
 182                 spin_lock_init(&ctx->gc_seq_lock);
 183                 atomic_set(&ctx->count,1);
 184         }
 185         return ctx;
 186 }
 187
 188 #define GSSD_MIN_TIMEOUT (60 * 60)
 189 static const void *
 190 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
 191 {
 192         const void *q;
 193         unsigned int seclen;
 194         unsigned int timeout;
 195         u32 window_size;
 196         int ret;
 197
 198         /* First unsigned int gives the lifetime (in seconds) of the cred */
 199         p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
 200         if (IS_ERR(p))
 201                 goto err;
 202         if (timeout == 0)
 203                 timeout = GSSD_MIN_TIMEOUT;
 204         ctx->gc_expiry = jiffies + (unsigned long)timeout * HZ * 3 / 4;
 205         /* Sequence number window. Determines the maximum number of simultaneous requests */
 206         p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
 207         if (IS_ERR(p))
 208                 goto err;
 209         ctx->gc_win = window_size;
 210         /* gssd signals an error by passing ctx->gc_win = 0: */
 211         if (ctx->gc_win == 0) {
 212                 /*
 213                  * in which case, p points to an error code. Anything other
 214                  * than -EKEYEXPIRED gets converted to -EACCES.
 215                  */
 216                 p = simple_get_bytes(p, end, &ret, sizeof(ret));
 217                 if (!IS_ERR(p))
 218                         p = (ret == -EKEYEXPIRED) ? ERR_PTR(-EKEYEXPIRED) :
 219                                                     ERR_PTR(-EACCES);
 220                 goto err;
 221         }
 222         /* copy the opaque wire context */
 223         p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
 224         if (IS_ERR(p))
 225                 goto err;
 226         /* import the opaque security context */
 227         p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
 228         if (IS_ERR(p))
 229                 goto err;
 230         q = (const void *)((const char *)p + seclen);
 231         if (unlikely(q > end || q < p)) {
 232                 p = ERR_PTR(-EFAULT);
 233                 goto err;
 234         }
 235         ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx, GFP_NOFS);
 236         if (ret < 0) {
 237                 p = ERR_PTR(ret);
 238                 goto err;
 239         }
 240         return q;
 241 err:
 242         dprintk("RPC:       gss_fill_context returning %ld\n", -PTR_ERR(p));
 243         return p;
 244 }
 245
 246 #define UPCALL_BUF_LEN 128
 247
 248 struct gss_upcall_msg {
 249         atomic_t count;
 250         uid_t   uid;
 251         struct rpc_pipe_msg msg;
 252         struct list_head list;
 253         struct gss_auth *auth;
 254         struct rpc_inode *inode;
 255         struct rpc_wait_queue rpc_waitqueue;
 256         wait_queue_head_t waitqueue;
 257         struct gss_cl_ctx *ctx;
 258         char databuf[UPCALL_BUF_LEN];
 259 };
 260
 261 static int get_pipe_version(void)
 262 {
 263         int ret;
 264
 265         spin_lock(&pipe_version_lock);
 266         if (pipe_version >= 0) {
 267                 atomic_inc(&pipe_users);
 268                 ret = pipe_version;
 269         } else
 270                 ret = -EAGAIN;
 271         spin_unlock(&pipe_version_lock);
 272         return ret;
 273 }
 274
 275 static void put_pipe_version(void)
 276 {
 277         if (atomic_dec_and_lock(&pipe_users, &pipe_version_lock)) {
 278                 pipe_version = -1;
 279                 spin_unlock(&pipe_version_lock);
 280         }
 281 }
 282
 283 static void
 284 gss_release_msg(struct gss_upcall_msg *gss_msg)
 285 {
 286         if (!atomic_dec_and_test(&gss_msg->count))
 287                 return;
 288         put_pipe_version();
 289         BUG_ON(!list_empty(&gss_msg->list));
 290         if (gss_msg->ctx != NULL)
 291                 gss_put_ctx(gss_msg->ctx);
 292         rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
 293         kfree(gss_msg);
 294 }
 295
 296 static struct gss_upcall_msg *
 297 __gss_find_upcall(struct rpc_inode *rpci, uid_t uid)
 298 {
 299         struct gss_upcall_msg *pos;
 300         list_for_each_entry(pos, &rpci->in_downcall, list) {
 301                 if (pos->uid != uid)
 302                         continue;
 303                 atomic_inc(&pos->count);
 304                 dprintk("RPC:       gss_find_upcall found msg %p\n", pos);
 305                 return pos;
 306         }
 307         dprintk("RPC:       gss_find_upcall found nothing\n");
 308         return NULL;
 309 }
 310
 311 /* Try to add an upcall to the pipefs queue.
 312  * If an upcall owned by our uid already exists, then we return a reference
 313  * to that upcall instead of adding the new upcall.
 314  */
 315 static inline struct gss_upcall_msg *
 316 gss_add_msg(struct gss_upcall_msg *gss_msg)
 317 {
 318         struct rpc_inode *rpci = gss_msg->inode;
 319         struct inode *inode = &rpci->vfs_inode;
 320         struct gss_upcall_msg *old;
 321
 322         spin_lock(&inode->i_lock);
 323         old = __gss_find_upcall(rpci, gss_msg->uid);
 324         if (old == NULL) {
 325                 atomic_inc(&gss_msg->count);
 326                 list_add(&gss_msg->list, &rpci->in_downcall);
 327         } else
 328                 gss_msg = old;
 329         spin_unlock(&inode->i_lock);
 330         return gss_msg;
 331 }
 332
 333 static void
 334 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 335 {
 336         list_del_init(&gss_msg->list);
 337         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 338         wake_up_all(&gss_msg->waitqueue);
 339         atomic_dec(&gss_msg->count);
 340 }
 341
 342 static void
 343 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 344 {
 345         struct inode *inode = &gss_msg->inode->vfs_inode;
 346
 347         if (list_empty(&gss_msg->list))
 348                 return;
 349         spin_lock(&inode->i_lock);
 350         if (!list_empty(&gss_msg->list))
 351                 __gss_unhash_msg(gss_msg);
 352         spin_unlock(&inode->i_lock);
 353 }
 354
 355 static void
 356 gss_handle_downcall_result(struct gss_cred *gss_cred, struct gss_upcall_msg *gss_msg)
 357 {
 358         switch (gss_msg->msg.errno) {
 359         case 0:
 360                 if (gss_msg->ctx == NULL)
 361                         break;
 362                 clear_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
 363                 gss_cred_set_ctx(&gss_cred->gc_base, gss_msg->ctx);
 364                 break;
 365         case -EKEYEXPIRED:
 366                 set_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
 367         }
 368         gss_cred->gc_upcall_timestamp = jiffies;
 369         gss_cred->gc_upcall = NULL;
 370         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 371 }
 372
 373 static void
 374 gss_upcall_callback(struct rpc_task *task)
 375 {
 376         struct gss_cred *gss_cred = container_of(task->tk_msg.rpc_cred,
 377                         struct gss_cred, gc_base);
 378         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
 379         struct inode *inode = &gss_msg->inode->vfs_inode;
 380
 381         spin_lock(&inode->i_lock);
 382         gss_handle_downcall_result(gss_cred, gss_msg);
 383         spin_unlock(&inode->i_lock);
 384         task->tk_status = gss_msg->msg.errno;
 385         gss_release_msg(gss_msg);
 386 }
 387
 388 static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg)
 389 {
 390         gss_msg->msg.data = &gss_msg->uid;
 391         gss_msg->msg.len = sizeof(gss_msg->uid);
 392 }
 393
 394 static void gss_encode_v1_msg(struct gss_upcall_msg *gss_msg,
 395                                 struct rpc_clnt *clnt, int machine_cred)
 396 {
 397         struct gss_api_mech *mech = gss_msg->auth->mech;
 398         char *p = gss_msg->databuf;
 399         int len = 0;
 400
 401         gss_msg->msg.len = sprintf(gss_msg->databuf, "mech=%s uid=%d ",
 402                                    mech->gm_name,
 403                                    gss_msg->uid);
 404         p += gss_msg->msg.len;
 405         if (clnt->cl_principal) {
 406                 len = sprintf(p, "target=%s ", clnt->cl_principal);
 407                 p += len;
 408                 gss_msg->msg.len += len;
 409         }
 410         if (machine_cred) {
 411                 len = sprintf(p, "service=* ");
 412                 p += len;
 413                 gss_msg->msg.len += len;
 414         } else if (!strcmp(clnt->cl_program->name, "nfs4_cb")) {
 415                 len = sprintf(p, "service=nfs ");
 416                 p += len;
 417                 gss_msg->msg.len += len;
 418         }
 419         if (mech->gm_upcall_enctypes) {
 420                 len = sprintf(p, mech->gm_upcall_enctypes);
 421                 p += len;
 422                 gss_msg->msg.len += len;
 423         }
 424         len = sprintf(p, "\n");
 425         gss_msg->msg.len += len;
 426
 427         gss_msg->msg.data = gss_msg->databuf;
 428         BUG_ON(gss_msg->msg.len > UPCALL_BUF_LEN);
 429 }
 430
 431 static void gss_encode_msg(struct gss_upcall_msg *gss_msg,
 432                                 struct rpc_clnt *clnt, int machine_cred)
 433 {
 434         if (pipe_version == 0)
 435                 gss_encode_v0_msg(gss_msg);
 436         else /* pipe_version == 1 */
 437                 gss_encode_v1_msg(gss_msg, clnt, machine_cred);
 438 }
 439
 440 static inline struct gss_upcall_msg *
 441 gss_alloc_msg(struct gss_auth *gss_auth, uid_t uid, struct rpc_clnt *clnt,
 442                 int machine_cred)
 443 {
 444         struct gss_upcall_msg *gss_msg;
 445         int vers;
 446
 447         gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
 448         if (gss_msg == NULL)
 449                 return ERR_PTR(-ENOMEM);
 450         vers = get_pipe_version();
 451         if (vers < 0) {
 452                 kfree(gss_msg);
 453                 return ERR_PTR(vers);
 454         }
 455         gss_msg->inode = RPC_I(gss_auth->dentry[vers]->d_inode);
 456         INIT_LIST_HEAD(&gss_msg->list);
 457         rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 458         init_waitqueue_head(&gss_msg->waitqueue);
 459         atomic_set(&gss_msg->count, 1);
 460         gss_msg->uid = uid;
 461         gss_msg->auth = gss_auth;
 462         gss_encode_msg(gss_msg, clnt, machine_cred);
 463         return gss_msg;
 464 }
 465
 466 static struct gss_upcall_msg *
 467 gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cred *cred)
 468 {
 469         struct gss_cred *gss_cred = container_of(cred,
 470                         struct gss_cred, gc_base);
 471         struct gss_upcall_msg *gss_new, *gss_msg;
 472         uid_t uid = cred->cr_uid;
 473
 474         gss_new = gss_alloc_msg(gss_auth, uid, clnt, gss_cred->gc_machine_cred);
 475         if (IS_ERR(gss_new))
 476                 return gss_new;
 477         gss_msg = gss_add_msg(gss_new);
 478         if (gss_msg == gss_new) {
 479                 struct inode *inode = &gss_new->inode->vfs_inode;
 480                 int res = rpc_queue_upcall(inode, &gss_new->msg);
 481                 if (res) {
 482                         gss_unhash_msg(gss_new);
 483                         gss_msg = ERR_PTR(res);
 484                 }
 485         } else
 486                 gss_release_msg(gss_new);
 487         return gss_msg;
 488 }
 489
 490 static void warn_gssd(void)
 491 {
 492         static unsigned long ratelimit;
 493         unsigned long now = jiffies;
 494
 495         if (time_after(now, ratelimit)) {
 496                 printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
 497                                 "Please check user daemon is running.\n");
 498                 ratelimit = now + 15*HZ;
 499         }
 500 }
 501
 502 static inline int
 503 gss_refresh_upcall(struct rpc_task *task)
 504 {
 505         struct rpc_cred *cred = task->tk_msg.rpc_cred;
 506         struct gss_auth *gss_auth = container_of(cred->cr_auth,
 507                         struct gss_auth, rpc_auth);
 508         struct gss_cred *gss_cred = container_of(cred,
 509                         struct gss_cred, gc_base);
 510         struct gss_upcall_msg *gss_msg;
 511         struct inode *inode;
 512         int err = 0;
 513
 514         dprintk("RPC: %5u gss_refresh_upcall for uid %u\n", task->tk_pid,
 515                                                                 cred->cr_uid);
 516         gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred);
 517         if (PTR_ERR(gss_msg) == -EAGAIN) {
 518                 /* XXX: warning on the first, under the assumption we
 519                  * shouldn't normally hit this case on a refresh. */
 520                 warn_gssd();
 521                 task->tk_timeout = 15*HZ;
 522                 rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
 523                 return 0;
 524         }
 525         if (IS_ERR(gss_msg)) {
 526                 err = PTR_ERR(gss_msg);
 527                 goto out;
 528         }
 529         inode = &gss_msg->inode->vfs_inode;
 530         spin_lock(&inode->i_lock);
 531         if (gss_cred->gc_upcall != NULL)
 532                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
 533         else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
 534                 task->tk_timeout = 0;
 535                 gss_cred->gc_upcall = gss_msg;
 536                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
 537                 atomic_inc(&gss_msg->count);
 538                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
 539         } else {
 540                 gss_handle_downcall_result(gss_cred, gss_msg);
 541                 err = gss_msg->msg.errno;
 542         }
 543         spin_unlock(&inode->i_lock);
 544         gss_release_msg(gss_msg);
 545 out:
 546         dprintk("RPC: %5u gss_refresh_upcall for uid %u result %d\n",
 547                         task->tk_pid, cred->cr_uid, err);
 548         return err;
 549 }
 550
 551 static inline int
 552 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 553 {
 554         struct inode *inode;
 555         struct rpc_cred *cred = &gss_cred->gc_base;
 556         struct gss_upcall_msg *gss_msg;
 557         DEFINE_WAIT(wait);
 558         int err = 0;
 559
 560         dprintk("RPC:       gss_upcall for uid %u\n", cred->cr_uid);
 561 retry:
 562         gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
 563         if (PTR_ERR(gss_msg) == -EAGAIN) {
 564                 err = wait_event_interruptible_timeout(pipe_version_waitqueue,
 565                                 pipe_version >= 0, 15*HZ);
 566                 if (err)
 567                         goto out;
 568                 if (pipe_version < 0)
 569                         warn_gssd();
 570                 goto retry;
 571         }
 572         if (IS_ERR(gss_msg)) {
 573                 err = PTR_ERR(gss_msg);
 574                 goto out;
 575         }
 576         inode = &gss_msg->inode->vfs_inode;
 577         for (;;) {
 578                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE);
 579                 spin_lock(&inode->i_lock);
 580                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 581                         break;
 582                 }
 583                 spin_unlock(&inode->i_lock);
 584                 if (signalled()) {
 585                         err = -ERESTARTSYS;
 586                         goto out_intr;
 587                 }
 588                 schedule();
 589         }
 590         if (gss_msg->ctx)
 591                 gss_cred_set_ctx(cred, gss_msg->ctx);
 592         else
 593                 err = gss_msg->msg.errno;
 594         spin_unlock(&inode->i_lock);
 595 out_intr:
 596         finish_wait(&gss_msg->waitqueue, &wait);
 597         gss_release_msg(gss_msg);
 598 out:
 599         dprintk("RPC:       gss_create_upcall for uid %u result %d\n",
 600                         cred->cr_uid, err);
 601         return err;
 602 }
 603
 604 static ssize_t
 605 gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
 606                 char __user *dst, size_t buflen)
 607 {
 608         char *data = (char *)msg->data + msg->copied;
 609         size_t mlen = min(msg->len, buflen);
 610         unsigned long left;
 611
 612         left = copy_to_user(dst, data, mlen);
 613         if (left == mlen) {
 614                 msg->errno = -EFAULT;
 615                 return -EFAULT;
 616         }
 617
 618         mlen -= left;
 619         msg->copied += mlen;
 620         msg->errno = 0;
 621         return mlen;
 622 }
 623
 624 #define MSG_BUF_MAXSIZE 1024
 625
 626 static ssize_t
 627 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 628 {
 629         const void *p, *end;
 630         void *buf;
 631         struct gss_upcall_msg *gss_msg;
 632         struct inode *inode = filp->f_path.dentry->d_inode;
 633         struct gss_cl_ctx *ctx;
 634         uid_t uid;
 635         ssize_t err = -EFBIG;
 636
 637         if (mlen > MSG_BUF_MAXSIZE)
 638                 goto out;
 639         err = -ENOMEM;
 640         buf = kmalloc(mlen, GFP_NOFS);
 641         if (!buf)
 642                 goto out;
 643
 644         err = -EFAULT;
 645         if (copy_from_user(buf, src, mlen))
 646                 goto err;
 647
 648         end = (const void *)((char *)buf + mlen);
 649         p = simple_get_bytes(buf, end, &uid, sizeof(uid));
 650         if (IS_ERR(p)) {
 651                 err = PTR_ERR(p);
 652                 goto err;
 653         }
 654
 655         err = -ENOMEM;
 656         ctx = gss_alloc_context();
 657         if (ctx == NULL)
 658                 goto err;
 659
 660         err = -ENOENT;
 661         /* Find a matching upcall */
 662         spin_lock(&inode->i_lock);
 663         gss_msg = __gss_find_upcall(RPC_I(inode), uid);
 664         if (gss_msg == NULL) {
 665                 spin_unlock(&inode->i_lock);
 666                 goto err_put_ctx;
 667         }
 668         list_del_init(&gss_msg->list);
 669         spin_unlock(&inode->i_lock);
 670
 671         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 672         if (IS_ERR(p)) {
 673                 err = PTR_ERR(p);
 674                 switch (err) {
 675                 case -EACCES:
 676                 case -EKEYEXPIRED:
 677                         gss_msg->msg.errno = err;
 678                         err = mlen;
 679                         break;
 680                 case -EFAULT:
 681                 case -ENOMEM:
 682                 case -EINVAL:
 683                 case -ENOSYS:
 684                         gss_msg->msg.errno = -EAGAIN;
 685                         break;
 686                 default:
 687                         printk(KERN_CRIT "%s: bad return from "
 688                                 "gss_fill_context: %zd\n", __func__, err);
 689                         BUG();
 690                 }
 691                 goto err_release_msg;
 692         }
 693         gss_msg->ctx = gss_get_ctx(ctx);
 694         err = mlen;
 695
 696 err_release_msg:
 697         spin_lock(&inode->i_lock);
 698         __gss_unhash_msg(gss_msg);
 699         spin_unlock(&inode->i_lock);
 700         gss_release_msg(gss_msg);
 701 err_put_ctx:
 702         gss_put_ctx(ctx);
 703 err:
 704         kfree(buf);
 705 out:
 706         dprintk("RPC:       gss_pipe_downcall returning %Zd\n", err);
 707         return err;
 708 }
 709
 710 static int gss_pipe_open(struct inode *inode, int new_version)
 711 {
 712         int ret = 0;
 713
 714         spin_lock(&pipe_version_lock);
 715         if (pipe_version < 0) {
 716                 /* First open of any gss pipe determines the version: */
 717                 pipe_version = new_version;
 718                 rpc_wake_up(&pipe_version_rpc_waitqueue);
 719                 wake_up(&pipe_version_waitqueue);
 720         } else if (pipe_version != new_version) {
 721                 /* Trying to open a pipe of a different version */
 722                 ret = -EBUSY;
 723                 goto out;
 724         }
 725         atomic_inc(&pipe_users);
 726 out:
 727         spin_unlock(&pipe_version_lock);
 728         return ret;
 729
 730 }
 731
 732 static int gss_pipe_open_v0(struct inode *inode)
 733 {
 734         return gss_pipe_open(inode, 0);
 735 }
 736
 737 static int gss_pipe_open_v1(struct inode *inode)
 738 {
 739         return gss_pipe_open(inode, 1);
 740 }
 741
 742 static void
 743 gss_pipe_release(struct inode *inode)
 744 {
 745         struct rpc_inode *rpci = RPC_I(inode);
 746         struct gss_upcall_msg *gss_msg;
 747
 748         spin_lock(&inode->i_lock);
 749         while (!list_empty(&rpci->in_downcall)) {
 750
 751                 gss_msg = list_entry(rpci->in_downcall.next,
 752                                 struct gss_upcall_msg, list);
 753                 gss_msg->msg.errno = -EPIPE;
 754                 atomic_inc(&gss_msg->count);
 755                 __gss_unhash_msg(gss_msg);
 756                 spin_unlock(&inode->i_lock);
 757                 gss_release_msg(gss_msg);
 758                 spin_lock(&inode->i_lock);
 759         }
 760         spin_unlock(&inode->i_lock);
 761
 762         put_pipe_version();
 763 }
 764
 765 static void
 766 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 767 {
 768         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 769
 770         if (msg->errno < 0) {
 771                 dprintk("RPC:       gss_pipe_destroy_msg releasing msg %p\n",
 772                                 gss_msg);
 773                 atomic_inc(&gss_msg->count);
 774                 gss_unhash_msg(gss_msg);
 775                 if (msg->errno == -ETIMEDOUT)
 776                         warn_gssd();
 777                 gss_release_msg(gss_msg);
 778         }
 779 }
 780
 781 /*
 782  * NOTE: we have the opportunity to use different
 783  * parameters based on the input flavor (which must be a pseudoflavor)
 784  */
 785 static struct rpc_auth *
 786 gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 787 {
 788         struct gss_auth *gss_auth;
 789         struct rpc_auth * auth;
 790         int err = -ENOMEM; /* XXX? */
 791
 792         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
 793
 794         if (!try_module_get(THIS_MODULE))
 795                 return ERR_PTR(err);
 796         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
 797                 goto out_dec;
 798         gss_auth->client = clnt;
 799         err = -EINVAL;
 800         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
 801         if (!gss_auth->mech) {
 802                 printk(KERN_WARNING "%s: Pseudoflavor %d not found!\n",
 803                                 __func__, flavor);
 804                 goto err_free;
 805         }
 806         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
 807         if (gss_auth->service == 0)
 808                 goto err_put_mech;
 809         auth = &gss_auth->rpc_auth;
 810         auth->au_cslack = GSS_CRED_SLACK >> 2;
 811         auth->au_rslack = GSS_VERF_SLACK >> 2;
 812         auth->au_ops = &authgss_ops;
 813         auth->au_flavor = flavor;
 814         atomic_set(&auth->au_count, 1);
 815         kref_init(&gss_auth->kref);
 816
 817         /*
 818          * Note: if we created the old pipe first, then someone who
 819          * examined the directory at the right moment might conclude
 820          * that we supported only the old pipe.  So we instead create
 821          * the new pipe first.
 822          */
 823         gss_auth->dentry[1] = rpc_mkpipe(clnt->cl_path.dentry,
 824                                          "gssd",
 825                                          clnt, &gss_upcall_ops_v1,
 826                                          RPC_PIPE_WAIT_FOR_OPEN);
 827         if (IS_ERR(gss_auth->dentry[1])) {
 828                 err = PTR_ERR(gss_auth->dentry[1]);
 829                 goto err_put_mech;
 830         }
 831
 832         gss_auth->dentry[0] = rpc_mkpipe(clnt->cl_path.dentry,
 833                                          gss_auth->mech->gm_name,
 834                                          clnt, &gss_upcall_ops_v0,
 835                                          RPC_PIPE_WAIT_FOR_OPEN);
 836         if (IS_ERR(gss_auth->dentry[0])) {
 837                 err = PTR_ERR(gss_auth->dentry[0]);
 838                 goto err_unlink_pipe_1;
 839         }
 840         err = rpcauth_init_credcache(auth);
 841         if (err)
 842                 goto err_unlink_pipe_0;
 843
 844         return auth;
 845 err_unlink_pipe_0:
 846         rpc_unlink(gss_auth->dentry[0]);
 847 err_unlink_pipe_1:
 848         rpc_unlink(gss_auth->dentry[1]);
 849 err_put_mech:
 850         gss_mech_put(gss_auth->mech);
 851 err_free:
 852         kfree(gss_auth);
 853 out_dec:
 854         module_put(THIS_MODULE);
 855         return ERR_PTR(err);
 856 }
 857
 858 static void
 859 gss_free(struct gss_auth *gss_auth)
 860 {
 861         rpc_unlink(gss_auth->dentry[1]);
 862         rpc_unlink(gss_auth->dentry[0]);
 863         gss_mech_put(gss_auth->mech);
 864
 865         kfree(gss_auth);
 866         module_put(THIS_MODULE);
 867 }
 868
 869 static void
 870 gss_free_callback(struct kref *kref)
 871 {
 872         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
 873
 874         gss_free(gss_auth);
 875 }
 876
 877 static void
 878 gss_destroy(struct rpc_auth *auth)
 879 {
 880         struct gss_auth *gss_auth;
 881
 882         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
 883                         auth, auth->au_flavor);
 884
 885         rpcauth_destroy_credcache(auth);
 886
 887         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
 888         kref_put(&gss_auth->kref, gss_free_callback);
 889 }
 890
 891 /*
 892  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
 893  * to the server with the GSS control procedure field set to
 894  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
 895  * all RPCSEC_GSS state associated with that context.
 896  */
 897 static int
 898 gss_destroying_context(struct rpc_cred *cred)
 899 {
 900         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 901         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 902         struct rpc_task *task;
 903
 904         if (gss_cred->gc_ctx == NULL ||
 905             test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
 906                 return 0;
 907
 908         gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
 909         cred->cr_ops = &gss_nullops;
 910
 911         /* Take a reference to ensure the cred will be destroyed either
 912          * by the RPC call or by the put_rpccred() below */
 913         get_rpccred(cred);
 914
 915         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
 916         if (!IS_ERR(task))
 917                 rpc_put_task(task);
 918
 919         put_rpccred(cred);
 920         return 1;
 921 }
 922
 923 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
 924  * to create a new cred or context, so they check that things have been
 925  * allocated before freeing them. */
 926 static void
 927 gss_do_free_ctx(struct gss_cl_ctx *ctx)
 928 {
 929         dprintk("RPC:       gss_free_ctx\n");
 930
 931         kfree(ctx->gc_wire_ctx.data);
 932         kfree(ctx);
 933 }
 934
 935 static void
 936 gss_free_ctx_callback(struct rcu_head *head)
 937 {
 938         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
 939         gss_do_free_ctx(ctx);
 940 }
 941
 942 static void
 943 gss_free_ctx(struct gss_cl_ctx *ctx)
 944 {
 945         struct gss_ctx *gc_gss_ctx;
 946
 947         gc_gss_ctx = rcu_dereference(ctx->gc_gss_ctx);
 948         rcu_assign_pointer(ctx->gc_gss_ctx, NULL);
 949         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
 950         if (gc_gss_ctx)
 951                 gss_delete_sec_context(&gc_gss_ctx);
 952 }
 953
 954 static void
 955 gss_free_cred(struct gss_cred *gss_cred)
 956 {
 957         dprintk("RPC:       gss_free_cred %p\n", gss_cred);
 958         kfree(gss_cred);
 959 }
 960
 961 static void
 962 gss_free_cred_callback(struct rcu_head *head)
 963 {
 964         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
 965         gss_free_cred(gss_cred);
 966 }
 967
 968 static void
 969 gss_destroy_nullcred(struct rpc_cred *cred)
 970 {
 971         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 972         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
 973         struct gss_cl_ctx *ctx = gss_cred->gc_ctx;
 974
 975         rcu_assign_pointer(gss_cred->gc_ctx, NULL);
 976         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
 977         if (ctx)
 978                 gss_put_ctx(ctx);
 979         kref_put(&gss_auth->kref, gss_free_callback);
 980 }
 981
 982 static void
 983 gss_destroy_cred(struct rpc_cred *cred)
 984 {
 985
 986         if (gss_destroying_context(cred))
 987                 return;
 988         gss_destroy_nullcred(cred);
 989 }
 990
 991 /*
 992  * Lookup RPCSEC_GSS cred for the current process
 993  */
 994 static struct rpc_cred *
 995 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 996 {
 997         return rpcauth_lookup_credcache(auth, acred, flags);
 998 }
 999
1000 static struct rpc_cred *
1001 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1002 {
1003         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1004         struct gss_cred *cred = NULL;
1005         int err = -ENOMEM;
1006
1007         dprintk("RPC:       gss_create_cred for uid %d, flavor %d\n",
1008                 acred->uid, auth->au_flavor);
1009
1010         if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS)))
1011                 goto out_err;
1012
1013         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
1014         /*
1015          * Note: in order to force a call to call_refresh(), we deliberately
1016          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
1017          */
1018         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
1019         cred->gc_service = gss_auth->service;
1020         cred->gc_machine_cred = acred->machine_cred;
1021         kref_get(&gss_auth->kref);
1022         return &cred->gc_base;
1023
1024 out_err:
1025         dprintk("RPC:       gss_create_cred failed with error %d\n", err);
1026         return ERR_PTR(err);
1027 }
1028
1029 static int
1030 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
1031 {
1032         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1033         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
1034         int err;
1035
1036         do {
1037                 err = gss_create_upcall(gss_auth, gss_cred);
1038         } while (err == -EAGAIN);
1039         return err;
1040 }
1041
1042 static int
1043 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1044 {
1045         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1046
1047         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1048                 goto out;
1049         /* Don't match with creds that have expired. */
1050         if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
1051                 return 0;
1052         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1053                 return 0;
1054 out:
1055         if (acred->machine_cred != gss_cred->gc_machine_cred)
1056                 return 0;
1057         return (rc->cr_uid == acred->uid);
1058 }
1059
1060 /*
1061 * Marshal credentials.
1062 * Maybe we should keep a cached credential for performance reasons.
1063 */
1064 static __be32 *
1065 gss_marshal(struct rpc_task *task, __be32 *p)
1066 {
1067         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1068         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1069                                                  gc_base);
1070         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
1071         __be32          *cred_len;
1072         struct rpc_rqst *req = task->tk_rqstp;
1073         u32             maj_stat = 0;
1074         struct xdr_netobj mic;
1075         struct kvec     iov;
1076         struct xdr_buf  verf_buf;
1077
1078         dprintk("RPC: %5u gss_marshal\n", task->tk_pid);
1079
1080         *p++ = htonl(RPC_AUTH_GSS);
1081         cred_len = p++;
1082
1083         spin_lock(&ctx->gc_seq_lock);
1084         req->rq_seqno = ctx->gc_seq++;
1085         spin_unlock(&ctx->gc_seq_lock);
1086
1087         *p++ = htonl((u32) RPC_GSS_VERSION);
1088         *p++ = htonl((u32) ctx->gc_proc);
1089         *p++ = htonl((u32) req->rq_seqno);
1090         *p++ = htonl((u32) gss_cred->gc_service);
1091         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1092         *cred_len = htonl((p - (cred_len + 1)) << 2);
1093
1094         /* We compute the checksum for the verifier over the xdr-encoded bytes
1095          * starting with the xid and ending at the end of the credential: */
1096         iov.iov_base = xprt_skip_transport_header(task->tk_xprt,
1097                                         req->rq_snd_buf.head[0].iov_base);
1098         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1099         xdr_buf_from_iov(&iov, &verf_buf);
1100
1101         /* set verifier flavor*/
1102         *p++ = htonl(RPC_AUTH_GSS);
1103
1104         mic.data = (u8 *)(p + 1);
1105         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1106         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1107                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1108         } else if (maj_stat != 0) {
1109                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
1110                 goto out_put_ctx;
1111         }
1112         p = xdr_encode_opaque(p, NULL, mic.len);
1113         gss_put_ctx(ctx);
1114         return p;
1115 out_put_ctx:
1116         gss_put_ctx(ctx);
1117         return NULL;
1118 }
1119
1120 static int gss_renew_cred(struct rpc_task *task)
1121 {
1122         struct rpc_cred *oldcred = task->tk_msg.rpc_cred;
1123         struct gss_cred *gss_cred = container_of(oldcred,
1124                                                  struct gss_cred,
1125                                                  gc_base);
1126         struct rpc_auth *auth = oldcred->cr_auth;
1127         struct auth_cred acred = {
1128                 .uid = oldcred->cr_uid,
1129                 .machine_cred = gss_cred->gc_machine_cred,
1130         };
1131         struct rpc_cred *new;
1132
1133         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1134         if (IS_ERR(new))
1135                 return PTR_ERR(new);
1136         task->tk_msg.rpc_cred = new;
1137         put_rpccred(oldcred);
1138         return 0;
1139 }
1140
1141 static int gss_cred_is_negative_entry(struct rpc_cred *cred)
1142 {
1143         if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) {
1144                 unsigned long now = jiffies;
1145                 unsigned long begin, expire;
1146                 struct gss_cred *gss_cred;
1147
1148                 gss_cred = container_of(cred, struct gss_cred, gc_base);
1149                 begin = gss_cred->gc_upcall_timestamp;
1150                 expire = begin + gss_expired_cred_retry_delay * HZ;
1151
1152                 if (time_in_range_open(now, begin, expire))
1153                         return 1;
1154         }
1155         return 0;
1156 }
1157
1158 /*
1159 * Refresh credentials. XXX - finish
1160 */
1161 static int
1162 gss_refresh(struct rpc_task *task)
1163 {
1164         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1165         int ret = 0;
1166
1167         if (gss_cred_is_negative_entry(cred))
1168                 return -EKEYEXPIRED;
1169
1170         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1171                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1172                 ret = gss_renew_cred(task);
1173                 if (ret < 0)
1174                         goto out;
1175                 cred = task->tk_msg.rpc_cred;
1176         }
1177
1178         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1179                 ret = gss_refresh_upcall(task);
1180 out:
1181         return ret;
1182 }
1183
1184 /* Dummy refresh routine: used only when destroying the context */
1185 static int
1186 gss_refresh_null(struct rpc_task *task)
1187 {
1188         return -EACCES;
1189 }
1190
1191 static __be32 *
1192 gss_validate(struct rpc_task *task, __be32 *p)
1193 {
1194         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1195         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1196         __be32          seq;
1197         struct kvec     iov;
1198         struct xdr_buf  verf_buf;
1199         struct xdr_netobj mic;
1200         u32             flav,len;
1201         u32             maj_stat;
1202
1203         dprintk("RPC: %5u gss_validate\n", task->tk_pid);
1204
1205         flav = ntohl(*p++);
1206         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1207                 goto out_bad;
1208         if (flav != RPC_AUTH_GSS)
1209                 goto out_bad;
1210         seq = htonl(task->tk_rqstp->rq_seqno);
1211         iov.iov_base = &seq;
1212         iov.iov_len = sizeof(seq);
1213         xdr_buf_from_iov(&iov, &verf_buf);
1214         mic.data = (u8 *)p;
1215         mic.len = len;
1216
1217         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1218         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1219                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1220         if (maj_stat) {
1221                 dprintk("RPC: %5u gss_validate: gss_verify_mic returned "
1222                                 "error 0x%08x\n", task->tk_pid, maj_stat);
1223                 goto out_bad;
1224         }
1225         /* We leave it to unwrap to calculate au_rslack. For now we just
1226          * calculate the length of the verifier: */
1227         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1228         gss_put_ctx(ctx);
1229         dprintk("RPC: %5u gss_validate: gss_verify_mic succeeded.\n",
1230                         task->tk_pid);
1231         return p + XDR_QUADLEN(len);
1232 out_bad:
1233         gss_put_ctx(ctx);
1234         dprintk("RPC: %5u gss_validate failed.\n", task->tk_pid);
1235         return NULL;
1236 }
1237
1238 static inline int
1239 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1240                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1241 {
1242         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1243         struct xdr_buf  integ_buf;
1244         __be32          *integ_len = NULL;
1245         struct xdr_netobj mic;
1246         u32             offset;
1247         __be32          *q;
1248         struct kvec     *iov;
1249         u32             maj_stat = 0;
1250         int             status = -EIO;
1251
1252         integ_len = p++;
1253         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1254         *p++ = htonl(rqstp->rq_seqno);
1255
1256         status = encode(rqstp, p, obj);
1257         if (status)
1258                 return status;
1259
1260         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1261                                 offset, snd_buf->len - offset))
1262                 return status;
1263         *integ_len = htonl(integ_buf.len);
1264
1265         /* guess whether we're in the head or the tail: */
1266         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1267                 iov = snd_buf->tail;
1268         else
1269                 iov = snd_buf->head;
1270         p = iov->iov_base + iov->iov_len;
1271         mic.data = (u8 *)(p + 1);
1272
1273         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1274         status = -EIO; /* XXX? */
1275         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1276                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1277         else if (maj_stat)
1278                 return status;
1279         q = xdr_encode_opaque(p, NULL, mic.len);
1280
1281         offset = (u8 *)q - (u8 *)p;
1282         iov->iov_len += offset;
1283         snd_buf->len += offset;
1284         return 0;
1285 }
1286
1287 static void
1288 priv_release_snd_buf(struct rpc_rqst *rqstp)
1289 {
1290         int i;
1291
1292         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1293                 __free_page(rqstp->rq_enc_pages[i]);
1294         kfree(rqstp->rq_enc_pages);
1295 }
1296
1297 static int
1298 alloc_enc_pages(struct rpc_rqst *rqstp)
1299 {
1300         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1301         int first, last, i;
1302
1303         if (snd_buf->page_len == 0) {
1304                 rqstp->rq_enc_pages_num = 0;
1305                 return 0;
1306         }
1307
1308         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1309         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
1310         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1311         rqstp->rq_enc_pages
1312                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1313                                 GFP_NOFS);
1314         if (!rqstp->rq_enc_pages)
1315                 goto out;
1316         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1317                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1318                 if (rqstp->rq_enc_pages[i] == NULL)
1319                         goto out_free;
1320         }
1321         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1322         return 0;
1323 out_free:
1324         rqstp->rq_enc_pages_num = i;
1325         priv_release_snd_buf(rqstp);
1326 out:
1327         return -EAGAIN;
1328 }
1329
1330 static inline int
1331 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1332                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1333 {
1334         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1335         u32             offset;
1336         u32             maj_stat;
1337         int             status;
1338         __be32          *opaque_len;
1339         struct page     **inpages;
1340         int             first;
1341         int             pad;
1342         struct kvec     *iov;
1343         char            *tmp;
1344
1345         opaque_len = p++;
1346         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1347         *p++ = htonl(rqstp->rq_seqno);
1348
1349         status = encode(rqstp, p, obj);
1350         if (status)
1351                 return status;
1352
1353         status = alloc_enc_pages(rqstp);
1354         if (status)
1355                 return status;
1356         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1357         inpages = snd_buf->pages + first;
1358         snd_buf->pages = rqstp->rq_enc_pages;
1359         snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
1360         /*
1361          * Give the tail its own page, in case we need extra space in the
1362          * head when wrapping:
1363          *
1364          * call_allocate() allocates twice the slack space required
1365          * by the authentication flavor to rq_callsize.
1366          * For GSS, slack is GSS_CRED_SLACK.
1367          */
1368         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1369                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1370                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1371                 snd_buf->tail[0].iov_base = tmp;
1372         }
1373         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1374         /* slack space should prevent this ever happening: */
1375         BUG_ON(snd_buf->len > snd_buf->buflen);
1376         status = -EIO;
1377         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1378          * done anyway, so it's safe to put the request on the wire: */
1379         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1380                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1381         else if (maj_stat)
1382                 return status;
1383
1384         *opaque_len = htonl(snd_buf->len - offset);
1385         /* guess whether we're in the head or the tail: */
1386         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1387                 iov = snd_buf->tail;
1388         else
1389                 iov = snd_buf->head;
1390         p = iov->iov_base + iov->iov_len;
1391         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1392         memset(p, 0, pad);
1393         iov->iov_len += pad;
1394         snd_buf->len += pad;
1395
1396         return 0;
1397 }
1398
1399 static int
1400 gss_wrap_req(struct rpc_task *task,
1401              kxdrproc_t encode, void *rqstp, __be32 *p, void *obj)
1402 {
1403         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1404         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1405                         gc_base);
1406         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1407         int             status = -EIO;
1408
1409         dprintk("RPC: %5u gss_wrap_req\n", task->tk_pid);
1410         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1411                 /* The spec seems a little ambiguous here, but I think that not
1412                  * wrapping context destruction requests makes the most sense.
1413                  */
1414                 status = encode(rqstp, p, obj);
1415                 goto out;
1416         }
1417         switch (gss_cred->gc_service) {
1418                 case RPC_GSS_SVC_NONE:
1419                         status = encode(rqstp, p, obj);
1420                         break;
1421                 case RPC_GSS_SVC_INTEGRITY:
1422                         status = gss_wrap_req_integ(cred, ctx, encode,
1423                                                                 rqstp, p, obj);
1424                         break;
1425                 case RPC_GSS_SVC_PRIVACY:
1426                         status = gss_wrap_req_priv(cred, ctx, encode,
1427                                         rqstp, p, obj);
1428                         break;
1429         }
1430 out:
1431         gss_put_ctx(ctx);
1432         dprintk("RPC: %5u gss_wrap_req returning %d\n", task->tk_pid, status);
1433         return status;
1434 }
1435
1436 static inline int
1437 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1438                 struct rpc_rqst *rqstp, __be32 **p)
1439 {
1440         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1441         struct xdr_buf integ_buf;
1442         struct xdr_netobj mic;
1443         u32 data_offset, mic_offset;
1444         u32 integ_len;
1445         u32 maj_stat;
1446         int status = -EIO;
1447
1448         integ_len = ntohl(*(*p)++);
1449         if (integ_len & 3)
1450                 return status;
1451         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1452         mic_offset = integ_len + data_offset;
1453         if (mic_offset > rcv_buf->len)
1454                 return status;
1455         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1456                 return status;
1457
1458         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1459                                 mic_offset - data_offset))
1460                 return status;
1461
1462         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1463                 return status;
1464
1465         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1466         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1467                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1468         if (maj_stat != GSS_S_COMPLETE)
1469                 return status;
1470         return 0;
1471 }
1472
1473 static inline int
1474 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1475                 struct rpc_rqst *rqstp, __be32 **p)
1476 {
1477         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1478         u32 offset;
1479         u32 opaque_len;
1480         u32 maj_stat;
1481         int status = -EIO;
1482
1483         opaque_len = ntohl(*(*p)++);
1484         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1485         if (offset + opaque_len > rcv_buf->len)
1486                 return status;
1487         /* remove padding: */
1488         rcv_buf->len = offset + opaque_len;
1489
1490         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1491         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1492                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1493         if (maj_stat != GSS_S_COMPLETE)
1494                 return status;
1495         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1496                 return status;
1497
1498         return 0;
1499 }
1500
1501
1502 static int
1503 gss_unwrap_resp(struct rpc_task *task,
1504                 kxdrproc_t decode, void *rqstp, __be32 *p, void *obj)
1505 {
1506         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1507         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1508                         gc_base);
1509         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1510         __be32          *savedp = p;
1511         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1512         int             savedlen = head->iov_len;
1513         int             status = -EIO;
1514
1515         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1516                 goto out_decode;
1517         switch (gss_cred->gc_service) {
1518                 case RPC_GSS_SVC_NONE:
1519                         break;
1520                 case RPC_GSS_SVC_INTEGRITY:
1521                         status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1522                         if (status)
1523                                 goto out;
1524                         break;
1525                 case RPC_GSS_SVC_PRIVACY:
1526                         status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1527                         if (status)
1528                                 goto out;
1529                         break;
1530         }
1531         /* take into account extra slack for integrity and privacy cases: */
1532         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1533                                                 + (savedlen - head->iov_len);
1534 out_decode:
1535         status = decode(rqstp, p, obj);
1536 out:
1537         gss_put_ctx(ctx);
1538         dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid,
1539                         status);
1540         return status;
1541 }
1542
1543 static const struct rpc_authops authgss_ops = {
1544         .owner          = THIS_MODULE,
1545         .au_flavor      = RPC_AUTH_GSS,
1546         .au_name        = "RPCSEC_GSS",
1547         .create         = gss_create,
1548         .destroy        = gss_destroy,
1549         .lookup_cred    = gss_lookup_cred,
1550         .crcreate       = gss_create_cred
1551 };
1552
1553 static const struct rpc_credops gss_credops = {
1554         .cr_name        = "AUTH_GSS",
1555         .crdestroy      = gss_destroy_cred,
1556         .cr_init        = gss_cred_init,
1557         .crbind         = rpcauth_generic_bind_cred,
1558         .crmatch        = gss_match,
1559         .crmarshal      = gss_marshal,
1560         .crrefresh      = gss_refresh,
1561         .crvalidate     = gss_validate,
1562         .crwrap_req     = gss_wrap_req,
1563         .crunwrap_resp  = gss_unwrap_resp,
1564 };
1565
1566 static const struct rpc_credops gss_nullops = {
1567         .cr_name        = "AUTH_GSS",
1568         .crdestroy      = gss_destroy_nullcred,
1569         .crbind         = rpcauth_generic_bind_cred,
1570         .crmatch        = gss_match,
1571         .crmarshal      = gss_marshal,
1572         .crrefresh      = gss_refresh_null,
1573         .crvalidate     = gss_validate,
1574         .crwrap_req     = gss_wrap_req,
1575         .crunwrap_resp  = gss_unwrap_resp,
1576 };
1577
1578 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
1579         .upcall         = gss_pipe_upcall,
1580         .downcall       = gss_pipe_downcall,
1581         .destroy_msg    = gss_pipe_destroy_msg,
1582         .open_pipe      = gss_pipe_open_v0,
1583         .release_pipe   = gss_pipe_release,
1584 };
1585
1586 static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
1587         .upcall         = gss_pipe_upcall,
1588         .downcall       = gss_pipe_downcall,
1589         .destroy_msg    = gss_pipe_destroy_msg,
1590         .open_pipe      = gss_pipe_open_v1,
1591         .release_pipe   = gss_pipe_release,
1592 };
1593
1594 /*
1595  * Initialize RPCSEC_GSS module
1596  */
1597 static int __init init_rpcsec_gss(void)
1598 {
1599         int err = 0;
1600
1601         err = rpcauth_register(&authgss_ops);
1602         if (err)
1603                 goto out;
1604         err = gss_svc_init();
1605         if (err)
1606                 goto out_unregister;
1607         rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
1608         return 0;
1609 out_unregister:
1610         rpcauth_unregister(&authgss_ops);
1611 out:
1612         return err;
1613 }
1614
1615 static void __exit exit_rpcsec_gss(void)
1616 {
1617         gss_svc_shutdown();
1618         rpcauth_unregister(&authgss_ops);
1619         rcu_barrier(); /* Wait for completion of call_rcu()'s */
1620 }
1621
1622 MODULE_LICENSE("GPL");
1623 module_param_named(expired_cred_retry_delay,
1624                    gss_expired_cred_retry_delay,
1625                    uint, 0644);
1626 MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until "
1627                 "the RPC engine retries an expired credential");
1628
1629 module_init(init_rpcsec_gss)
1630 module_exit(exit_rpcsec_gss)